The present invention relates to an engine starter switch device provided with an immobilizer coil.
In recent years, an immobilizer system has been developed in a vehicle such as an automobile, for the purpose of preventing theft. The immobilizer system has such a structure that a transponder is provided in a portable key or a portable device, while an immobilizer coil for two-way transmission is provided in an engine starter switch device of the vehicle, and an ID code of the transponder side and an ID code of the vehicle side are compared, so that an engine is allowed to start only when collation of them has been established.
FIGS. 6 to 10 show an example of a conventional engine starter switch device of this type. In FIGS. 8 to 10, a coil bobbin 2 in an annular shape is assembled to a front part of a body 1. An immobilizer coil 3 (See FIG. 9) is mounted to the coil bobbin 2, and coil connecting terminals 4 for connecting a starting end and a terminal end of the immobilizer coil 3 are also provided on the coil bobbin 2 by insert molding. An insulator 5 is assembled to the body 1 at a position behind the coil bobbin 2. A fixed contact 6 (See FIG. 9), terminals 7 for electronic components, and terminals 8 for connectors are provided on the insulator 5 by insert molding. Moreover, the insulator 5 is equipped with an LED 9a for an indicator and an LED 9b for night illumination, both of which are the electronic components. These LEDs 9a, 9b are connected to the aforesaid terminals 7 for the electronic components. Further, a wiring board 10 formed of a printed board is disposed inside the body 1. The wiring board 10 is provided with coil connecting terminal connecting parts 10a, electronic component terminal connecting parts 10b, and connector terminal connecting parts 10c in a shape of through hole.
The aforesaid coil connecting terminals 4 are inserted into the coil connecting terminal connecting parts 10a, and fixed by soldering, the aforesaid terminals 7 for the electronic components are inserted into the electronic component terminal connecting parts 10b and fixed by soldering, and the aforesaid terminals 8 for the connectors are inserted into the connector terminal connecting parts 10c and fixed by soldering.
A bezel 11 in a ring-like shape is attached to a front part of the body 1, and an operating knob 12 of a push-button type for an engine starter switch is arranged inside this bezel 11. Moreover, a holder 13 is disposed inside the body 1, and connected to the operating knob 12. Both the operating knob 12 and the holder 13 can move along an axial direction of the body 1. These operating knob 12 and holder 13 are urged forward by a return spring 14 (See FIG. 8). Movable contacts 15 are provided on the holder 13, in such a manner that the movable contacts 15 may be contacted with and separated from the aforesaid fixed contact 6, following the movement of the holder 13. The engine starter switch 16 (See FIG. 9) is composed of the movable contacts 15 and the fixed contact 6. Therefore, the engine starter switch 16 is so constructed as to be actuated by pushing operation of the operating knob 12.
Further, the operating knob 12 is provided with an opening 12a for the indicator. A lens 17 having an indicator part 17a in a front part thereof is provided behind this opening 12a. This lens 17 guides a light of the aforesaid LED 9a to the indicator part 17a to light it up. Moreover, a detent spring 18a and a ball 18b are provided between the holder 13 and the insulator 5. A cover 19 is mounted on an outer periphery of the body 1 so as to cover a side opening 1a of the body 1. In FIG. 8, reference numeral 20 represents cushions for absorbing sound of a shock when the holder 13 moves.
In the conventional structure as described above, there is a problem as follows. The coil connecting terminals 4 of the coil bobbin 2, and the electronic component terminals 7 and the connector terminals 8 of the insulator 5 are respectively soldered to the same wiring board 10. However, the coil bobbin 2 and the insulator 5 are separate members, and respectively assembled to the body 1. For this reason, particularly, those areas where the coil connecting terminals 4 are soldered to the wiring board 10 are influenced by thermal expansion and shrinkage of the insulator 5, the body 1 and the coil bobbin 2, due to a change of environmental temperature (a thermal impact) of the vehicle. Consequently, the soldered areas of the coil connecting terminals 4 are subjected to a larger stress than the areas where the electronic component terminals 7 and the connector terminals 8 on the aforesaid insulator 5 are soldered to the wiring board 10. There is such anxiety that a crack may occur in the soldered areas, when the aforesaid thermal impact is repeated, and faulty electrical continuity may occur.
Although not directly concerned with the problem of the invention, a structure of an engine starter switch provided with an immobilizer coil is disclosed in Japanese Patent Publication No. JP-A-2006-273025.
The invention has been made in view of the above described circumstances, and an object of the invention is to provide an engine starter switch device in which a stress exerted on soldered areas between coil connecting terminals to which ends of the immobilizer coil are connected and a wiring board can be moderated to the substantially same extent as a stress exerted on soldered areas between terminals at an insulator side and the wiring board, whereby occurrence of faulty electrical continuity in the soldered areas between the coil connecting terminals and the wiring board can be prevented.